The absence of satellite signals in indoor environments has given way to the rise of indoor positioning and indoor navigation systems resulting in the indoor location market being estimated to reach $4.4 Billion by 2019.
Arguably, there is not currently a single, widely accepted solution that can achieve the desired accuracy at the required cost. One possible reason for this may be the varying requirements for indoor localisation systems, such as: applications, accuracy, size, battery life, maintenance, plug-n-play, mobility, etc.
GPS transformed the way that people navigate outdoors. Accurate indoor localisation has the potential to have a similar effect. This can provide the foundation for accurate location-aware services, such navigating through indoor environments or accessing local devices, on a wireless local area network (LAN). Such networks are commonplace, and accurate indoor localisation can greatly improve the value of such networks.
Indoor localisation is becoming increasingly important in the United States of America where the Federal Communications Commission (FCC) has mandated that cellular network operators accurately locate people calling 911. This previously only included outdoor localisation; however, in January 2015 the FCC introduced a requirement for indoor localisation. There is therefore a need for a more accurate means of determining the position of devices, particularly for use in indoor environments.